NIGEL Gets To Kno_ Logic An Experiment in Natural Language Generation Taking a Logical, Knowledge-Based View

This paper argues for using logic as the internal meaning representation language for natural language generators. We present our efforts in realizing such an interface for the natural language generator NIGEL. The language is a restricted first-order logic enhanced by some non-standard quantifiers. A network knowledge base organizes the concepts of the application domain appearing as predicates in the logical express ions into categories known by the generator. The logical express ions are interpreted by NIGEL using the hybrid knowledge representation system KL-TWO.l 1. Ilft'ID)UCTION It is commonly agreed upon that DBtural l~ ~tiQD can be divided into two sub-tasks, a strategie planning task responsible for planning the overall text, and a tactical task doing the actual generation on the sentence level. Furthermore, arguing from modularity among other reasons, most authors agree on using two more or less independent components for this purpose. If one accepts a design with two independent components, the quest ion arises how to design the interface between the components, in particular how the dd'e.IIlM6r,. of the